The new period drama on Showtime (9 p.m. Sunday) chronicles the personal and professional lives of William Masters and Virginia Johnson, the legendary team that pioneered the science of sexuality in the '50s and '60s. It's frank, provocative, educational and, yes, sexy.

Not for the prudish, the 12-episode series bursts with explicit depictions of sex — in the lab, in the bedroom, in a brothel. Some scenes feel warmly intimate, while others come across as cold and awkward, particularly those featuring naked human subjects under fluorescent lights who are wired to machines to measure their reactions to stimuli.

Surprisingly, these situations never feel gratuitous; however, they do occasionally prompt chuckles.

She was referring to a scene early on that has ob-gyn doctor Masters (Michael Sheen) demonstrating to the boss at his teaching hospital (Bridges) a female subject's response to a massive mechanical pleasure device.

“Inherently, some of the situations that we're depicting on this show are ridiculous,” Caplan said, “but they're factually accurate, and it's what they really did to come to the conclusions that they came to. So we weren't trying to pull a bunch of jokes or anything, but I do think that there are definitely moments of levity.”

Though sex is clearly a big part of “Masters,” it's only one aspect of this richly satisfying series. It's full of engaging characters, absorbing storylines and poignant moments.

“The more you think that you are watching a show about sex,” Sheen said, “the more you ultimately are watching a show about the challenges of just connecting with human beings.”

The first several episodes take us back to 1956, when sex still was a hush-hush mystery. We meet Masters during a clever juxtaposition of his two lives. He's being celebrated for his medical brilliance at a gala dinner for patrons of his university hospital. In the next scene, he's hiding in a dingy closet and observing a prostitute having relations with a customer so he can time and record her responses.

Later, during a chat with the prostitute, he's shocked when she not only reveals she usually fakes her orgasm, but that most women do the same.

“Seriously,” she tells him, “if you really want to learn about sex, you're going to have to get yourself a female partner.”

That statement speaks volumes about the doctor. Though a scientist ahead of his time in the lab, he remains firmly ensconced in the repressed 1950s at home, particularly when engaging in perfunctory sex with his wife, Libby (played with heartbreaking sensitivity by Caitlin Fitzgerald).

He presents quite a contrast to Johnson, the single mom who eventually becomes his research assistant and, much later, his second wife.

“She's very sexually adventurous,” Caplan said of her character.

As such, she contributes greatly to Masters' work and also awakens something powerful inside him that this controlled man never experienced before — causing him to both resent and obsess over her.

“Masters” boasts too many standout performances to count — from Nicholas D'Agosto as ambitious doctor Ethan Haas, who's bitter about being rejected by Johnson, to Ann Dowd as the mom who looked the other way during Masters' abusive childhood. The one that will stay with you, however, is Sheen. The Welsh actor, who is best known for his roles as former Prime Minister Tony Blair (“The Queen”) and talk host David Frost (“Frost/Nixon”), both infuriated me with his rigidity and tore my heart apart when he finally lets go in an emotional scene that cries for an Emmy.

What I appreciated the most about “Masters,” though, is how empowering it is. Even a modern woman like myself came away from the first six episodes feeling enlightened and somehow less alone.

“By doing a show about this in the way that we are trying to do it,” Sheen said, “it allows people to not feel so disconnected, to feel a little bit more connected, a little less shameful. I think if it can do that, then it's done its job.”

Jeanne Jakle's column appears Wednesdays and Sundays in mySA, and she blogs at Jakle's Jacuzzi on mySA.com. Email her at jjakle@express-news.net.